Modern computer networks strive for transparency of the physical network. Various utilities and applications are available for providing a user with a similar login experience regardless of location, enabling trends such as telecommuting and virtual private networks (VPNs). In a Virtual Local Area Network (VLAN), for example, users in distinct physical networks employ transport services that appear to be part of the same LAN. The IEEE 802.1aq standard of Shortest Path Bridging (SPB) networks extends the well entrenched Ethernet approach for accommodating virtual LANs and wireless transport. Multiple paths coexist such that a shortest path with minimal latency is automatically created and if there is a failure of a link or switch, the failover time is minimal. SPB also removes the complexity of manual VLAN extensions and avoids the somewhat cumbersome spanning tree protocol.
In an SPBM network, mechanisms are employed to debug connectivity issues and to isolate faults. Utilities and applications such as Connectivity Fault Management (CFM) are often employed for performing network management tasks for assessing and maintaining network health. Such utilities interrogate, report and assist in the diagnosis of connectivity and network path management operations, typically at the bequest of a network operator charged with maintenance of these networks.